1. Field of the Invention
The present invention relates to an information providing system which detects physiological condition of a driver who is driving a vehicle and gives any necessary warning to the driver.
2. Description of the Related Art
Recently, systems have been developed which detect physiological conditions of a vehicle driver such as sleepiness, fatigue, and fretfulness (irritation) during driving and alert the driver to these conditions, thereby encouraging him/her to drive safely.
For example, a system disclosed in Japanese Patent Laid-Open No. 8-140949 detects physiological conditions of a driver such as sleepiness, fatigue, and fretfulness and alerts the driver to any such condition, based on biomedical information such as heartbeat, respiration, fluctuations in heartbeat, and nictitation detected in the driver and road travel data of the vehicle obtained from a navigation system. This makes it possible to detect physiological conditions such as sleepiness, fatigue, fretfulness, etc. of the driver and give warnings even when the vehicle is running.
Such a conventional system issues a warning when the driver is sleepy, tired, fretting, etc. However, when the driver is experiencing, for example, sleepiness, the driver is already in a dangerous situation and even if a warning is issued in such a dangerous case, it is often too late to avoid danger by taking appropriate measures quickly.
Also, the driver can realize, for example, his/her sleepiness all right, but due to errors, the time when the sleepiness is detected by the conventional system does not necessarily coincide with the time when it is realized by the driver. This may bother the driver.
Also, there are great individual variations in biomedical information such as heartbeat, respiration, fluctuations in heartbeat, and nictitation. Thus, conventional systems, which do not take individual variations into consideration, may make an erroneous judgment if the driver changes.
Furthermore, for example, if the driver still has a long way to drive when sleepiness is detected, he/she must be warned, but if the driver arrives soon, he/she need not be warned. However, conventional systems do not give consideration to arrival time.